Appendix D
Example oj Force Predictions jor Use
with Hand Calculation Procedures
Problem:
Determine wind and current force predictions for use witb the hand calculation procedure for a
250,000 dwt tanker for the conditions listed below.
Wind load calculations
Step 1: Determine the vessel's characteristics.
Vessel particulars for a 250 kdwl tanker in a fully loaded condition are
AI. (Longitudinal or Bro adside Wind Area) = .)l r rn'
Ar(Transverse or Head-on Wind Area) = 818 m^1
Step 2: Obtain wind coefficient at Ow = 1500
Cx", = -0. 73 Figure 2.4
C YA •. = + 0.19 Figure 2.3
C YF" = + 0.13 Figure 2.3
Slep 3: Compute wind forces from equations
where:
FrAW
Pw
= Cxw(~) V~Ar
7600
= C~w(7~~) V~AL
v w = 60 knots
= (_ 0.73)(1.223)(60)1(818)
7600
-346 kN
FyAw = (+0.19)(~·:n(60)"(3225) +346 kN
Fyp." = (+0.13)(~-:)(60)2(3225) = +243 kN